Why does my baby hate me?

my son is turning 2 soon and he acts as if hates my guts he love his daddy to bits, he looks around 4 his dad but neva for me, we both work but when we return home together he runs up to his dad than me he does not wont to know me he loves his grandma and acts like she is his mum and not me. i do so much for my son but he will always go to his dad also when i touch him he cries or moves my hand away. am depressed please help!!!!!!!!!!!!!!!!!!!!!!